Method and apparatus for treating fluids and solids



J. MILTON Jan. 9, 1940.

METHOD AND APPARATUS FOR TREATING FLUIDS AND SOLIDS Original Filed Feb. 25, 1932 2 Sh eets-Sheet. 1

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Jam 1940- J. L. MILTON I 2,186,033

METHOD AND APPARATUS FOR TREATING FLUIDS AND SOLIDS Original Filed Feb. 25, 1932 2 Sheets-Sheet 2 Patented Jan. 9.1940;

UITE s'm-s NT OF E METHOD AND APPARATUS FOR TREATING FLUIDS AND SOLIDS John]; Milton, Louisville, Ky.

Application February 25,1932, Serial No. 595,124 Renewed May 4, 1936 23 Claims. (01.259-50) This invention is predicated upon the principle of combining solids and fiuids by centrifugal force for eflecting suspensions and/or impregnation.

Production of colloids and particularly regen- 5 erated milk and synthetic cream from milk powders; dispersing barytes, magnesium carbonate,

- zinc oxide, litharge, calcium, magnesium oxide, et

jects. A further object is to homogenize the product where desirable. To this end a rotatable container or containers with, axial means of ingress and peripheral means of egress for liquids and go solids are provided together with means for separately delivering liquids and solids to the container or processing area as required to effect automatic continuous production.

A structure employing a single or a pair of 25 rotatable faced bowls co axially disposed and fashioned with closely adjacent annular angularly disposed peripheral faces, of frustro-conical form correlated and actuated to control egress of products supplies the nucleus of the mill around and 30 to which are assembled several coordinating units all of which cooperate to process the raw materials into the finished product. 'I'he liquid and solids to be treated can be introduced to the processing area by means of stationary ducts ar- 35 ranged co-axially with hollow driving shafts of the bowls.

In Figure 1 of the drawings aifixed to this specification and forming part thereof, a pair of faced rotatable centrifugal bowls are illustrated princicarries concentric stationary ducts to which are attached conduits for the admission of the raw materials from delivery sources equipped with means for actuating said materials for trans- 45 ference.

Fig. 1A is an enlarged cross sectional viewof the tensioning device shown at the left side of Fig. 1. Fig. 1B is an enlarged vertical cross. sectional view of the distributor head (part 40). Fig. -1C is 50 an enlarged horizontal cross sectional view along line lc, Fig. 1B. Fig.2 is a diagrammatic crosssectional view of a pair of processing bowls tobe substituted for those shown in Fig. 1. Fig. 3 is a diagrammatic cross-sectional view of a modified 55 bowl, which can be substituted for the one shown in Fig. 1. Fig. 4 shows a still further modification of a processing bowl, shown mainly in cross section. Fig. 5 is a modification of Fig. 2 to indicate the reverse relation of the bowl and the impedance flange.

I is an inverted conical top bo'wl constructed with a hollow shaft ll rotatably mounted in an axially adjustable sleeve l2 carried by housing l3, with which companion housing l4 completes a processing chamber A. I is lowerconical bowl carried by hollow shaft l6, which is rotatably mounted in housing M. .i'! is an auxiliary 'inverted bowl entirely free' fromthe top bowl but attached to the lower bowl and contacting only at remote spots, as at l8, therebyleaving gaps IQ for the remainder of the circumference. In the hub of bowl l5 are a plurality of diagonally disposed ducts to establish communications to subchaxnber B, which is closed at the top by stationary plate Ida having a central opening 23 therein. 2 Attached to bowl I5 is a fan rotor 2| having circumferentially disposed openin'gs 22 and located adjacent to and in communication with the opening 23 in plate Ma so that the fan will pull air from the chamber 0 or container formed by the two major bowls l0 and I5 via ducts 20. Inasmuch as the peripheral faces Illa and Ho of the major bowls l0 and ii are normally closely positioned as indicated by Cl, the air drawn from the chamber 0 will necessarily be replaced by air 80 drawn through the input duct 24. It will be observed that the duct 24 is concentrically located with the major bowls l0 and l5.by flanged collar 25 and serves to convey the dry solids from thefeed hoppers 3|, 32. Bowl I0 is rotatably mounted on ball bearings, which ball bearings are fixedly mounted in sleeve I2. Sleeve I2 is slidably mounted for reciprocation in the cylindrical bearing in the top of hous- 40 pally in cross-section disposed in a housing which ing l3. Collar 25 is fixedly secured to the upper 40 end of sleeve l2 and also slidably engages duct 24, which duct 24 is concentrically located by the said collar. Sleeve I2 is floatingly secured to housing l3, by the tensioning device 21, which tensioning device is shown in Figure 1A The tensioning device 21 consists of a shouldered screw 21c having a threaded end fixedly secured to the housing l3 as shown in Figure 1A. 'I-hescrew 21c is also provided with a lower shouldered section having adiameter less than the holein the flange 59 of sleeve l2 through which the shouldered section passes. This construction and relation is clearly shown in Figure 1A. Accordingly, the sleeve I2 is free to reciprocate within the cylindrical 1n the tonal the housing l3. To limit 5 .sure is exerted on the bowl, as hereinafter explained, the sleeve l2 moves upwardly in the cylindrical bearing in housing l3 and overpowers the springs 21a of the tensioning device.

Referring in particular to Figure 1A, it will be observed that springs 21a surround the large shouldered section and react between the head of the screw 21c and the upper face of the flange on sleeve I2. Accordingly, the sleeve l2 and bowl I 0 are yieldingly forced downwardly by the springs 21a. While I have illustrated but one tensioning device in Figure 1, it is to be understood that three such devices are employed and distributed equallyabout the circumference of the flange of sleeve l2.

Referring now to Figure 1, it will be observed that a screw 26 is also mounted in the flange of sleeve l2. Screw 26 is employed to limit the downward travel of sleeve l2 and to accordingly adjust bowl ID in terms of bowl l5, so as to fixedly determine the minimum clearance between the peripheral faces Illa and l5a. Hereinafter, screws 26 will be referred to as down stops. I

From the foregoing it will be obvious that screws 26 may be adjusted to, in efiect, rigidly secure sleeve l2 to the housing l3 by raising the upper face of the flange on sleeve l2 into engagement with the upper shouldered section of the screw 210. Thus, the limiting devices control the normal space or gap between faces 10a and i511 according to the setting determined by down stops 26. These can be set so that the faces will actually contact, thereby producing in effect a single bowl which under suflicient internal pressure, produced by the action of centrifugal force-on the materials under process, will cause the faces to separate or crack and thereby liberate or extrude the product subject to the squeezing action of springs 210, which will incidentally produce an effective homogenizing action. It should be noted that under these conditions, the top bowl rides or floats on the materials under process. Should the up stops of the limiting device 21 beset to determine the gap between the faces,=and the product exert pressure beyond the strength of the springs, then the up stop willtemporarily determine the maximum gap.

Duct 24 is slidably mounted incollar 25 and is in communication with angularly disposed supply duct 28 which in turn is in communication with settling chamber D via vertical duct 29. D is connected to chamber A by drain duct 30. Attached to 28 is feed hopper 3| arranged to deliver solids to the floor of baflle plate 3la while hopper 32 also attached to duct 28 delivers solids to the inner bottom surface of said duct. Spring 33 .is arranged to suspend one end of duct 28 while flexible coupling 34, such as rubber, suspends the other end, thereby substantially float- :ing duct 28 and the depending input tube in order that it can readily respond to rapid vibrations produced by an A- C. vibrator motor 35 which may be constructed of a yoke 35a, coil 35b, and armature 35c carried by flat spring 3511 to which the duct is attached. The rapid vibrations of the motor are employed not only to agitate the solids to enable the gas currents to carry them to their destination but to prevent the particles from i in the conduit. When a completely closed system is to be employed duct 28b is connected as shown for equalizing pressure between the hoppers, which are necessarily closed, and duct 28. It is obvious that an atmosphere of a selected gas can be substituted for air. Shaft 38, which is driven by motor M carries fan rotor 39 and is mounted in the small ball bearings, the top one of which is carried in a head at concentrically attached to standpipe ll which is concentrically mounted in head l2, the latter is fixed to housing M. The standpipe is constructed in the clear of the inner walls of bowl shaft 56, while the bottom is mounted in head 42, and is equipped with a suitable plub 38a to seal it fromcommunicatiofi with the interior of the standpipe, which carries an inner pipe llb to seal the shaft 38 and to form the liquid input duct Ma. established between the two pipes 41, Mb. Head MI, Fig. 13, carrying the upper ball bearing 38!, is formed with an inner annular groove 40b in communication with duct Ma. A plurality of elbows 4001 are in com-' by causing the gas vehicle to pass through or intermingle with said film as it proceeds on its way through said ducts irom chamber A. This is provided for the removal of any entrained solid particles that were not previously removed from the gas vehicle or to cause an engagement or con tact between the gas or fluid leaving the mixing chamber A with the liquid or fluid entering same through head 40a. A similar arrangement is provided in Fig. 4, where disc 39| forces a film of the incoming material over exits 20. Duct a connects with a liquid supply such as a pump (not shown), operated at a ratio fixed interms of the solids supply, through duct 45 located in head 42. This whole sub-assembly being organized to convey liquid from an external source to chamber 0.

Operation In operation power is supplied to the bowl 15 preferably by a belt as indicated. After a selected speed has been attained liquid is fed in through duct 45, ascends and is discharged on to hub of said rotating bowl whereupon it is thrown out over the inner surface and ascends the inner surface of the bowl i5 imimpeded, except for normal minor resistances, until it reaches the film surface established by surfaces illa, l5a. The top bowl III is then brought into rotation due to the crowding of the liquid between said surfaces. To intensify the resistance, bowl I0 is held or retarded, preferably by a belt (not shown) which is put into motion by the pulley. The other end of this belt passm over a pulley attached to the shaft of a dynamo electric machine, preferably of the direct current type, and is used as a dynamo with externally excited fields in order to eifectively control the retardance of bowl l0 over a wide range of speeds. However, this can be a motor and the speed of rotation advanced, retarded or reversed in terms of bowl 15.

It should he noted that the structure provides processed and ejected without being subjected to agitation such as is produced by the action of heaters and agitators, or turbulence which follows subjecting liquid to the action of two correlated bowls or a bowl and an impeller operating at different speeds or in the opposite direction one to the other. Since the liquid is not agitated, although it is under rotation and in radial motion during the processing, it. is sometimes herein referred to as being in a quiescent state.

With bowl IS in operation, liquid is fed through'ducts 45 and Ma and will ascend and build up in chamber C until it establishes a vertical cylindrical level wall Ca, the inside diameter of which is determined by ducts 20. Excess liquid' will be discharged through said ducts and be forced into chamber B where it. will pass out through duct Ba and returned to the supply tank (not shown). Fan 2| simultaneously withdraws air from chamber C through duct 20 into chamber B as explained supra. Fan blades 39 contribute to the egress of this air and simultaneously are employed to discharge particles into'the wall of liquid, said particles being drawn in through input duct 25. The action of these blades can be regarded as a medium for transferring the solids from the gas stream to the liquid. Centrifugal force is imparted to the particles and carries them through the wall, where they are stripped of entrained removable gas, such as absorbed and/or adhering gas. The solids thus impregnated are forced on through the liquid. The particles being of heavier specific gravity tend to collect at and in the peripheral opening- It will beseen that the revolving liquid has been freed of at least certain gases and that as the particles are transferred into this rotating wall the removable air of the solids will also be eliminated, thereby continuously effecting a relatively perfect impregnation of the particles. This expression is used relatively and is not intended to convey the idea of a never ending process, rather to distinguish from the batch method. v

To prevent turbulence incident to bowl l5 being driven at a speed varying from bowl I0, auxiliary bowl I! is provided with the gaps l9 as explained supra. The product passes through these gaps into chamber C2 and is discharged in a dispersed and/or attenuated state from aperture Cl into the chamber A where it flows over the inner wall thereof and gravitates to the bottom from where it can be drawn from the machine through duct 30 into settling tank D. The same means provides egress for'the gas.

The established gas pressure is transmitted to vertical duct 29, Da. being provided for use as a vent under certain conditions. The gas currents are transmitted to diagonally disposed or incline; .duct 28 into which is fed the solids via hoppers 3|, '32 where unit 28 and its appurtenances are. subjected to rapid vibration in order that the fines can be suspended in the gas currents and the coarse aggregates separated and permitted to respond to gravity and drop into duct 28a where they can be collected or passedthrough rolls or other pulverizing means and returned to the system. Floor 3 la is angularly disposed to the bottom of 28 in order that lighter or more responsive solids, such as magnesium c'arbonate, can be simultaneously fed with heavier ones, such as'zinc oxide, through individual hoppers to provide means for feeding dissimilar constituents. A screw conveyor can be substituted for the feeding method just described.

Modifications In the modified structure shown in Fig. 2 a

stationary inverted bowl ill is substituted for bowl' 10 shown in Fig. l which is constructed to cooperate with lower bowl 5| provided with inner bowl l1 and fashioned with face Sla disposed at a lesser angle to theaxis of rotation than that employed in the former bowl, in order that centrifugal force will tend to impinge the product more vigorously against the working face than if a greater angle to the axis were selected and thereby hold the product in the bowl for a longer period where desired as when very light particles are under treatment, which would inherently be slower in responding to the centrifugal impregnating forces. This feature will also be useful for delaying the expulsion of the liquid in order to keep it in step with the conveyance of the particles to the liquid for impregnation and/or suspension, especially where an abnormally slow treatment is desired and when the rotor is op-' erated at relatively high speeds and provides facilities for assisting in controlling or balancing the output to the input of the constitutents de-1 livered by the'feeding apparatus, particularly where automatic control is involved. As a further means of impeding the outflow of the product, annular flange 52 angularly extending towards the axis of rotation 'of the rotor is attached to the rotor and overlaps the stator substantially as shown, however the drawing is not intended to dictate proportions or exact relations as these factors can be varied according to the behavior of the materials under process and to favor the desired results. As shown in Fig. 5., the rotor and stator can be reorganized so that the stator 50 will carry the impedance flange MI and effect a further retarding action on the materials under process. It should be noted that numeral 5 designates the main rotating bowl, and that inverted bowl Ill is mounted thereon.

As another effective means for impeding the outflow of the product, when desirable, the bowls can be operated in opposite directions in order that the resultant forces on the product confined between the operating faces will tend to neutralization and thereby prolong the duration for forcing the solids into the liquid wall. The modifled structure indicated in Fig. 3 is especially adaptable to these conditions. Bowls 60 and 6| have facesBlla and Ma which may be of the same or different area and the speed of rotation can be the same or varied.

To provide means for mixing and/or impregnating highly abrasive materials suchv as silica and cement with liquid without excessive damage to the mill, the structure shown in Fig.

4 can be employed. Bowl 10 is substituted for bowl l5, however inverted, while ring 'II is carriedin fixed relation thereto by bowl 10 at spaced sections'designated by IN. This arrangement results in arouate gaps IN. There are no working surfaces provided at the peripheral'outlet 12,.

tween face we and ring I8. Centrifugal force,

tends to keep ring 13 against face 10a which effect is of special use during starting, which is preferably lower than the operating speed, when liquid; is introduced in advance of the solids. Numeral 39a designates fan blades that are carried by shaft 390. Shaft 390 also carries a disc 39!. Suspended solids are fed through duct 39b and are forced by fan 39a into the wall of liquid Ca, while liquid is fed through the hollow shaft of the upper bowl and deposited on the disc 39!, which disc is carried and rotated by shaft 390. The liquid deposited on the disc is thrown outwardly and accordingly forms an annular spray. The annular spray forms a veiling over the exit ducts 20] and functions to arrest the entrained fine particles that failed to respond to the centrifugal action of the fan. This structure and action corresponds to that described for similar parts in Fig. 1. I Obviously fan 2 corresponds to 2! in Fig. 1.

Scope Although a closed system of feeding and operating the apparatus is shown and described, it can be adapted for communication with the atmosphere in whole by omission of duct 29, or in part, by opening vent Da. without departing from the essential principles.

The two bowls selected to disclose this in-- vention have their abutting faces fitted by mutual abrasion to function as a unitary structure, however, they can be replaced by a single bowl particularly in cases where the normal gas content of the solids is to be replaced with a heavy gas and this step is to be followed by impregnation or a coating operation. It is obvious, that for this method of procedure, the solids must be delivered into the processing bowl in advance of the liquid. Further, the speed of rotation can be varied for each step, et cetera, all without departing from the disclosed fundamental, principles.

I claim: I Y

1. A process of continuously mixing dry particles with liquid having lower specific gravity comprising, continuously advancing liquid into a vessel, continuously rotating the vessel at a velocity suiiicient to establish and maintain a hollow body of the liquid within the vessel, continuously delivering dry particles into the inner surface of the hollow body, and continuously discharging the particles mixed with the liquid from the vessel.

2. A process of continuously mixing dry material with a liquid having a lower specific gravity, comprising, continuously advancing a liquid into a vessel, continuously rotating the vessel at a velocity sufiicient to establish and maintain a hollow body of the liquid within the vessel, continuously delivering the dry material to the inner surface of the hollow body, centrifugally moving the material through the liquid forming the hollow body, and continuously discharging the material mixed with the liquid from the vessel.

3. A process of mixing dry material with a liquid having a lower specific gravity, comprising, delivering the liquid into a vessel, rotating the vessel at a velocity sufficient to establish and maintain a hollow body of the liquid within thevessel, delivering the dry material to the inner surface of the hollow body and centrifugally moving the material-through the liquid forming the hollow body.

4. A method of impregnating one material with a second material which consists in subjecting the first material to centrifugal force, while maintaining same in a quiescent state, subsequently centrifugally forcing the second material into the first materials and removing gases from both material by said centrifugal force.

5. A process of suspending dry solids in liquid, comprising, continuously advancing a stream of liquid to the inner periphery of a rotatingvesselto establish and maintain a. substantially quiescent cylindrical wall of said liquid, and continuously advancing a supply of dry solids adjacent the center of said vessel so as to contact the liquid in said rotating vessel and continuously discharging the product.

6. A process of suspending dry solids in liquid by centrifugal force, comprising, continuously advancing a stream of liquid to a rotating vessel while maintaining said liquid in a quiescent state, and continuously advancing a supply of solids to unite with the liquid in saidrotating vessel, and continuously discharging the product from the periphery of said vessel.

7. A process of suspending dry solids in liquid by centrifugal force, comprising, continuously advancing a stream of liquid to a rotating vessel while maintaining the interiorly disposed surface of said liquid in a quiescent state, and continuously advancing a supply of solids adjacent the axis of said vessel to unite with said surface of the liquid in said rotating vessel, and continuously discharging the product.

8. A process for suspending dry solids in liquid by centrifugal force, comprising continuously advancing a stream of liquid to a rotating vessel while maintaining same in a quiescent state and continuously advancing a supply of said solids into the interior of said vessel where said solids are centrifugally forced to unite with the liquid.

9. A method of combining liquid and dry matter which consists of continuously forcing minute solids into a rotating Wall of liquid by throwing minute solids from a gas stream into said rotating liquid and eliminating all the gas of said stream; continuously supplying liquid and solids to the wall continuously discharging the product while maintaining said wall at a predetermined cylindrical level.

10. A process of suspending dry solids in liquid, which consists of feeding conglomerate fine and coarse solids into a vibrating duct in which an air stream suspends and conveys said solids to and discharges same into a body of revolving liquid where said solids are suspended in said liquid.

11. A process of suspending dry solids in liquid,

which consists of feeding conglomerate fine and are discharged and suspended in said liquid.

13. The method of suspending solids in liquid which comprises, conveying solids by a gas stream into a rotating body of liquid, removing the solids from the gas and depositing said solids in the liquid and passing the gas stream through a film of liquid as it leavessaid body.

14. In an apparatus for efiecting suspensions,

comprising, a bowl mounted on an axis, means for conveying and delivering solids to the interior of the bowl, other means for conveying and delivering liquid to the interior of the bowl, a rotatable member within the bowl to operate on said solids and means to simultaneously rotate said bowl and said rotatable member at diiferent speeds.

15. An apparatus for forcing dry solid particles into liquid and simultaneously excluding gas, comprising, rotatable members having annular working surfaces; means for spacing said surfaces, means for rotating said rotatable members so that the working surfaces move past each otler; means for separately introducing particles and said liquid into the rotatable members; pneumatic means for conducting the dry particles into said members, centrifugally radially forcing the particles into the rotating liquid and means for ejecting the product from the junction of said surfaces.

16. An apparatus for impregnating dry solids with liquid, comprising, a rotating member; independent means for introducing liquid and a pneumatic stream for introducing solids into said member; means for centrifugally forcing said solids from said stream into said liquid and means for simultaneously excluding gases from said solids.

17. An apparatus for impregnating dry solids with fluid, comprising, rotatable bowls having annular faces; means yieldingly securing said faces'in closed relation to form a chamber, and provide a homogenizing element; means for rotating the bowls; means for conveying said dry "solids into the rotating chamber and centrifugal means for substituting fluid for the gas insaid solids.

18. An apparatus for impregnating dry solids with fluid, comprising, rotatable bowls having annular faces; means yieldingly securing said faces in closed relation to form a chamber, means for rotating the bowls; means for conveying saiddry solids'into the rotating chamber and centrifugal means for substituting fluid for the gas in said solids.

19. In an apparatus of the centrifugal type, a rotating bowl in three sections, two sections of which are secured together and define between them an annular chamber having a flxedoutlet at the periphery of one section and adjacent the periphery of its companion section while two of said sections define between them an annular chamber having a peripheral outlet.

20. A centrifuge for effecting a mixture of dry solids and liquid and homogenizing said mixture, comprising, a pair of bowls rotatable together as a unit; pneumatic means for supplying said solids and other means for delivering liquid into said bowls, means for centrifugally forcing said solids into said liquid and means for expelling said mixture through an homogenizing element constituting a. part of each of said bowls.

21. Mixing apparatus comprising a mixing receptacle, a supply container for powdered material; means agitating said material in said supply container to eifect flow therefrom; means continuously conducting said flow of powdered material from said su ply container into said.-

receptacle, a source of supply of liquid material, means effecting the flow of said liquid material, means introducing said flow of liquid into said receptacle, and means continuously mixing the materials in said receptacle.

22. Mixing apparatus comprising a mixing receptacle, a supply container for powdered material, means agitating said material in said supply container to effect flow therefrom, means continuously conducting said flow of powdered material from said supply container into said receptacle, a source of supply of liquid material; means effecting the flow of said liquid material; means introducing said flow of liquid intosaid receptacle; means continuously mixing the materials in said receptacle, and means continuously discharging said materials after mixing.

23. Mixing apparatus comprising a mixing re-' ceptacle, a supply container for powdered material above said receptacle, means agitating said material in said supply container to effect flow of said powdered material therefrom, means continuously conducting said flow of powdered material from said supply container into said receptacle, a source of supply of liquid material, means introducing said liquid into said receptacle, and means continuously mixing the materials in said receptacle, said receptacle having means providing a continuous overflow of the material processed therein.

' JOHN L. MILTON. 

